#desalination

Oceanic Water Vapor As The New Source of Fresh WaterWith the demand for water increasing every year, a lot of people don’t have access to clean and safe drinking water. At our estimate, over one billion people have this issue.Easy access to water is one of the most basic rights we should have. The lack of accessibility to this need moved experts to find alternative sources of water. While the option of obtaining seawater is there, the costs of removing the salt from them are expensive and energy-intensive. It will require specially-made desalination plants for people to constantly access drinkable seawater.A recent study published in the journal Scientific Reports has proposed a potential water source: the air above our oceans. This is because oceanic water vapor is usually there as long as the sun shines above the oceans. University of Illinois’ civil and environmental engineering professor Praveen Kumar and his colleagues proposed capturing the moisture via towering structures offshore. Once these buildings have successfully obtained the vapor, it will then be sent onshore where it can be condensed to become freshwater.As a proof of concept, the researchers analyzed the amount of oceanic water vapor available at 14 different locations around the globe from the year 1990 to 2019. Their calculations showed that their proposed towering structures could extract enough to meet the daily needs of around 500,000 people.Image credit: Kumar et.al via Scientific Reports#research #water #seawater #freshwater #desalination #alternative #ScientificReports

MIT Researchers Developed a $4 Solar-Powered Desalination System out of Everyday MaterialsA team of researchers at MIT and in China developed a desalination system that is more efficient and less expensive than previously established methods. The hope is that it will help solve shortages of water in different areas of the globe. The researchers focused on creating a design that also deals with the accumulation of salt over time. “The challenge has been the salt fouling issue, that people haven’t really addressed. So, we see these very attractive performance numbers, but they’re often limited because of longevity. Over time, things will foul,” Evelyn Wang, one of the researchers in the study, said. The resulting apparatus is a layered system. A dark material is at the top to absorb the sun’s heat, and a thin layer of water above a perforated layer of material sits atop the designated container of the salty water. The perforated material, made of polyurethane, has holes that are 2.5 millimeters in diameter, which is what the researchers deemed to be the optimal size that allows for a natural convective circulation between the warmer upper layer of water and the colder reservoir below. This prevents the salt from accumulating. Further work and testing would be required to test the device in large settings and long runs, according to Hadi Ghasemi, a professor of chemical and biomolecular engineering at the University of Houston.Image credit: Wang, et.al via MIT News #desalination #system #MIT #China

Solar Desalination with Biomass: Using Manure to Turn Seawater Into FreshwaterSafe water is one of the big problems that our planet is facing. UNICEF states that there are about 1.42 billion people who live in areas with scarce and vulnerable water. Out of these people, 450 million are children.To solve this, engineers tried to create freshwater from seawater. The results of these were desalination systems — systems that filtered out salt from seawater. However, it is an expensive solution. Is there a more affordable way to solve the world's water problem? Yi Zheng probably also asked the same question of himself. And when he visited a local dairy farm one summer day, he found something that inspired him to take on the problem. Manure.When he asked for a bucket of manure from the farmer for study, the latter did not hesitate and gave his request "free of charge." And when he did study it in his laboratory, the Northeastern professor found something rather interesting.When heated up to 1,700°C, the powdered carbon produced from the manure could be used as a desalinator. What's more interesting is that the desalinated water turned out to have a lower sodium concentration than the set standard by the U.S. Environmental Protection Agency for drinking water.More about this over at News at Northeastern.(All Images: Alyssa Stone/Northeastern University)#DrinkingWater #Desalination #Freshwater #UNICEF